Do not inherit TaskPriority in TaskTraits.

base/task_scheduler/task_traits.cc

Index: base/task_scheduler/task_traits.cc
diff --git a/base/task_scheduler/task_traits.cc b/base/task_scheduler/task_traits.cc
index 6acf3244f59e475c51ee21a1741ba94259fbfdf3..c00ae6c48cd1d60e1326a5e507df6e99d8c2cf26 100644
--- a/base/task_scheduler/task_traits.cc
+++ b/base/task_scheduler/task_traits.cc
@@ -9,19 +9,10 @@
 #include <ostream>
 
 #include "base/logging.h"
-#include "base/task_scheduler/scoped_set_task_priority_for_current_thread.h"
 
 namespace base {
 
-// Do not rely on defaults hard-coded below beyond the guarantees described in
-// the header; anything else is subject to change. Tasks should explicitly
-// request defaults if the behavior is critical to the task.
-TaskTraits::TaskTraits()
-    : may_block_(false),
-      with_base_sync_primitives_(false),
-      priority_(internal::GetTaskPriorityForCurrentThread()),
-      shutdown_behavior_(TaskShutdownBehavior::SKIP_ON_SHUTDOWN) {}
-
+TaskTraits::TaskTraits() = default;
 TaskTraits::~TaskTraits() = default;
 
 TaskTraits& TaskTraits::MayBlock() {
@@ -35,6 +26,7 @@ TaskTraits& TaskTraits::WithBaseSyncPrimitives() {
 }
 
 TaskTraits& TaskTraits::WithPriority(TaskPriority priority) {
+  priority_set_explicitly_ = true;
   priority_ = priority;
   return *this;
 }